Featured Research

from universities, journals, and other organizations

It takes a community of soil microbes to protect plants from disease

Date:

May 7, 2011

Source:

DOE/Lawrence Berkeley National Laboratory

Summary:

Plants rely on a tight-knit army of soil microbes to defend themselves against pathogens, much the way mammals harbor a raft of microbes to avoid infections. The discovery could help scientists develop ways to better protect the world's food crops from devastating diseases. The scientists deciphered, for the first time, the group of microbes that enables a patch of soil to suppress a plant-killing pathogen

Share This

In a development that could lead to better ways to protect food crops from disease, Berkeley Lab scientists unraveled the community of soil microbes that protect sugar beets from root fungus. From left, Todd DeSantis, Gary Andersen, and Yvette Piceno in the lab where much of the research was conducted. Several PhyloChips are on the table next to them.

Those vegetables you had for dinner may have once been protected by an immune system akin to the one that helps you fight disease. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the Netherland's Wageningen University found that plants rely on a complex community of soil microbes to defend themselves against pathogens, much the way mammals harbor a raft of microbes to avoid infections.

Related Articles

The scientists deciphered, for the first time, the group of microbes that enables a patch of soil to suppress a plant-killing pathogen. Previous research on the phenomenon of disease-suppressive soil had identified one or two pathogen-fighting microbes at work.

But the Berkeley Lab-led team found a complex microbial network. After analyzing soil from a sugar beet field that had become resistant to a pathogen that causes root fungus, the scientists found 17 soil microbes fighting to suppress the pathogen. They also determined that all of the microbes work together to reduce the incidence of fungal infection. Their discovery that plants use a tight-knit army of soil microbes for defense could help scientists develop ways to better protect the world's food crops from devastating diseases.

"Individual organisms have been associated with disease-suppressive soil before, but we demonstrated that many organisms in combination are associated with this phenomenon," says Gary Andersen of Berkeley Lab's Earth Sciences Division. He conducted the research with fellow Berkeley Lab scientists Todd DeSantis and Yvette Piceno as well as several scientists from the Netherlands including Wageningen University's Jos Raaijmakers. Their research is published in the May 5 issue of Science Express.

The Berkeley Lab and Dutch scientists analyzed soil from a sugar beet field in the Netherlands. Something in the soil suppressed the presence of the pathogen Rhizoctonia solani, which causes root fungus in beets, potato, and rice.

The sugar beets' health followed the typical arc of plants in disease-suppressive soil: they enjoyed a few good years, then they succumbed to disease, followed by healthy beets again as pathogen-fighting microbes were activated and the soil became hostile to R. solani. To return the favor, the sugar beets funnel about a fifth of their photosynthetically captured carbon through their roots into the soil to fuel the microbes.

Disease-suppressive soils are quite common, and scientists have identified some of the microbes involved in this underground immune system. But they don't know all of the microbes that participate.

To find out, the scientists used the PhyloChip, which is a credit-card sized chip that can detect the presence of 59,000 species of bacteria and archaea in samples of air, water, and soil without the need of culturing. It was developed at Berkeley Lab to rapidly identify not only the most common and abundant organisms in an environmental sample, but also very rare types that are present in extremely small numbers. It does this by comparing a DNA sequences unique to each bacterial species with over one million reference DNA targets on the chip. The PhyloChip has shed light on many environmental mysteries, such as what's killing coral reefs near Puerto Rico and what degraded much of the oil from the Gulf of Mexico's Deepwater Horizon spill.

In this case, soil samples from the sugar beet field were modified to exhibit six levels of disease suppression. DNA was isolated from the samples and sent to Berkeley Lab for analysis. The PhyloChip detected more than 33,000 bacterial and archaeal species in the samples, with all six having more or less the same types of bacteria.

But when the scientists looked at the abundance of bacteria in each sample, they found that each had a unique fingerprint. All of the samples in which disease was suppressed had a greater abundance of 17 unique types of bacteria. These included well-known fungal fighters such as Psuedomonas, Burkholderia, Xanthomonas and Actinobacteria. In addition, other types of bacteria that have no demonstrated ability to fight pathogens on their own were found to act synergistically to suppress plant disease.

Based on this, the scientists believe that an uptick in several bacterial types is a more important indicator of disease suppression than the presence of one or two bacteria that are especially good at killing pathogens.

"We now see that the complex phenomenon of disease suppression in soils cannot simply be attributed to a single bacterial group, but is most likely controlled by a community of organisms," says Andersen.

Their research will help scientists pursue unanswered questions about disease-suppressive soil: Do plants actively recruit beneficial soil microorganisms for protection against infection? And if so, how do they do it? It will also help scientists elucidate the mechanisms by which groups of soil microbes work together to reduce the incidence of plant disease.

The research was supported in part by the California Environmental Protection Agency's State Water Resources Control Board and the Rathmann Family Foundation.

DOE/Lawrence Berkeley National Laboratory. "It takes a community of soil microbes to protect plants from disease." ScienceDaily. ScienceDaily, 7 May 2011. <www.sciencedaily.com/releases/2011/05/110505161001.htm>.

DOE/Lawrence Berkeley National Laboratory. (2011, May 7). It takes a community of soil microbes to protect plants from disease. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2011/05/110505161001.htm

DOE/Lawrence Berkeley National Laboratory. "It takes a community of soil microbes to protect plants from disease." ScienceDaily. www.sciencedaily.com/releases/2011/05/110505161001.htm (accessed March 3, 2015).

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015 — Two of the four known groups of human AIDS viruses (HIV-1 groups O and P) have originated in western lowland gorillas, according to new research. The scientists conducted a comprehensive survey of ... full story

Mar. 2, 2015 — For the first time, researchers have produced a 3-D image revealing part of the inner structure of an intact, infectious virus, using a unique X-ray laser. The virus, called Mimivirus, is in a ... full story

Mar. 2, 2015 — In the first study of its kind since the 1920s, rats in New York City were found to carry a flea species capable of transmitting plague pathogens. Among them: 500-plus Oriental rat fleas, notorious ... full story

Mar. 2, 2015 — What do a human colon, septic tank, copper nanoparticles and zebrafish have in common? They were the key components used by researchers to study the impact copper nanoparticles, which are found in ... full story

Mar. 2, 2015 — You might resemble or act more like your mother, but a novel research study reveals that mammals are genetically more like their dads. Specifically, the research shows that although we inherit equal ... full story

Mar. 2, 2015 — Researchers have examined the association of nut and peanut consumption with mortality among low-income and racially diverse populations and found that intake of peanuts was associated with fewer ... full story

Mar. 2, 2015 — Hungry, plant-eating insects may limit the ability of forests to take up elevated levels of carbon dioxide in the atmosphere, reducing their capacity to slow human-driven climate change, a new study ... full story

Mar. 2, 2015 — A higher intake by postmenopausal women of the natural antioxidant lycopene, found in foods like tomatoes, watermelon and papaya, may lower the risk of renal cell carcinoma, a type of kidney cancer, ... full story

Mar. 2, 2015 — Researchers have characterized the gut microbiome of honey bee queens. This is the first thorough census of the gut microbiome -- which consists of all the microorganisms that live in the gut of the ... full story

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015) — Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

Oct. 28, 2014 — Variation in antibiotic-producing microbes in tropical forest soils has been discovered by scientists, who not that this research represents a step toward better understanding of the role they play ... full story

Mar. 25, 2014 — Using high-powered DNA-based tools, a recent study identified soil microbes that negatively affect ragweed and provided a new understanding of the complex relationships going on beneath the soil ... full story

July 18, 2013 — Shift in soil microbes triggers cycle to improve yield, plant nutrition and disease resistance. New research could help explain the dramatic effect on soil health and yield of crop ... full story

Aug. 14, 2012 — Soil microbes are impulsive. So much so that they help plants face the challenges of a rapidly changing climate. Biologists have studied how plants and microbes work together to help plants survive ... full story

July 17, 2012 — Scientists searching for clues to understand how superweeds obtain resistance to the popular herbicide glyphosate may have been missing a critical piece of information, a study ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.